Modern movie projector tends to adopt cartridgized reels for the simplification of operation.
In the field of movie projection, many famous manufacturers such as Kodak, and Bell & Howell have cartridgized their small size films. Bolex even dramatized the effect by introducing a so called "Multi-cassette" system. Yet, each has the same disadvantage that at least one auxiliary spool is needed externally of the cartridge or cassette. One cannot remove the cartridge or cassette in the middle of projection but has to wait until the whole reel is finished running or rewinding. As for another brand "Technicolor", an endless cartridge has been offered to meet a different purpose such as displaying in exhibition or advertisement. The endless type doesn't give the possibility for fast forward and rewinding and hence offers less selectivity. Also, large intersurface friction causes damage to the film.